1. Field of the Invention
This invention relates to a suspension for a vehicle, and more particularly to a suspension provided with a shock absorber capable of adjusting a damping force.
2. Description of the Prior Art
When a piston rod of a shock absorber is connected to a car body, a construction is employed in which a rubber bushing is interposed between the piston rod and the car body to prevent the car body from vibration transmitted from the shock absorber. This applies also to the case of the shock absorber capable of adjusting the damping force.
The bushing cannot change the spring constant after the shape or the like is defined as predetermined to be incorporated in the car body, except for few examples (for example, Japanese Utility Model Public Disclosure (KOKAI) No. 76837/83, since the spring constant is absolutely determined.
U.S. patent application Ser. No. 753,785 (filed July 11, 1985, now U.S. Pat. No. 4,651,977) relates to a construction for connecting a shock absorber having a piston rod to a car body. In this construction, the bushing disposed radially outward of a valve base connected to the piston rod has a plurality of fluid chambers. Communication between a plurality of the fluid chambers is afforded and interrupted by a valve body disposed in the valve base. However, the damping force of the shock absorber cannot be adjusted.